from itertools import combinations

N = int(input())
S = input()
A = list(map(int, input().split()))

Sum = [0] * (N+1)
for i in range(N):
    Sum[i+1] = Sum[i] + (A[i] if S[i] == 'R' else -A[i])
    
Max = 0
for l, r in combinations(range(N+1), 2):
    Max = max(Max, abs(Sum[l] - Sum[r]))
    
print(Max)